Dear Lammps users,

I am using lammps-16May18 version to do free-energy calculations using ABF method. Dihedral is my colvar. I broked my reaction coordinate into five windows and the first window spans from 0 to 46 degree, When I performing the free energy calculations I found that in .traj file the dihedral is reaching negative dihedral angles (eg: -52). To avoid this I have used hardlowerbound on but I didn’t see any difference.

As far as I know, this hardlowerbound will set to natural lower limit to the function(colvar). {eg: In case of distance lower limit is 0}

Can anyone please tell me how to restrict my simulations in specified boundaries. Moreover, In the previous versions, there is an option called lowerwallconstant which is not there in the latest version.

I want to calculate the correlation length for the series of biasing forces for that I have to get the instantaneous force on the colvar. From the documentation, I found that “**Outputappliedforce on**” gives the magnitude of the force. But from the simulations, I found that the force is zero. There is another option “**OutputTotalForce on**” which gives me non-zero forces under (fk_{name}) name. The distribution of the fk_{name} looks like Gaussian distribution. So please tell me which forces I have to take to calculate error bars.

Thanks,

Divya.